This invention relates to a new and improved apparatus which is utilized to at least partially form a plurality of airfoils or other articles by electrolytically removing material from the workpiece.
Machines have been utilized to form airfoils by the electrolytic removal of material from a workpiece. One of these machines is disclosed in U.S. Pat. No. 3,554,892. The machine disclosed in this patent utilizes a pair of cathode electrodes to form turbine blades or airfoils one at a time in an elongated workpiece. A machine constructed generally in accordance with this patent is effective to sequentially form a plurality of airfoils. It has been suggested that each electrode of this machine could be provided with a plurality of fixedly interconnected face surfaces to simultaneously form a plurality of airfoils.
Machines for sequentially operating on a plurality of workpieces to form airfoils by electrolytically removing material have been described. Since these machines simultaneously operate on a plurality of workpieces to form airfoils, the rate of production of these machines may be somewhat greater than the production rate of a machine which operates on only a single workpiece to form one airfoil at a time. Machines in which material is moved from a workpiece at each of a series of work stations in turn by electrochemical operations to form airfoils are disclosed in U.S. Pat. Nos. 3,459,645 and 3,466,235. It should be noted that these patents contemplate that the workpiece will be moved in succession to each of a plurality of work stations and do not contemplate the forming of a plurality of turbine blades or airfoils at one work station. Other known prior art devices which utilize a plurality of electrodes to electrolytically remove material from a workpiece are disclosed in U.S. Pat. Nos. 3,594,298; 3,547,797; 3,436,311 and 3,287,245.
The machines disclosed in the aforementioned prior art patents all contemplate that a flow of electroylte will be established between a workpiece which forms an anode electrode and a cathode electrode having a working or face surface with a configuration corresponding to the desired configuration of the workpiece. In many prior art machines which are utilized to form airfoils, this flow of electrolyte has been directed between the leading and trailing edge portions of the airfoil in the manner disclosed in U.S. Pat. No. 3,372,099. However, it has also been suggested that an electrode could be moved axially along an airfoil and the flow of electrolyte conducted axially along the surface of the airfoil in the direction of movement of the electrode in the manner described in U.S. Pat. No. 3,803,009.
Although most prior art machines move the electrodes in a direction which is perpendicular to the major side surface of a workpiece in the manner disclosed in U.S. Pat. No. 3,554,892, during certain electrochemical machining operations an electrode has been moved along a path extending at an angle to a side surface of a workpiece. Thus, in U.S. Pat. No. 3,795,604 a tubular electrode for drilling small holes is moved at an acute angle in the major side surface of a workpiece. It should be noted that this patent does not contemplate moving a plurality of electrodes at acute angles relative to the workpiece to form opposite sides of an airfoil.